This invention generally relates to devices for inspecting the properties or condition of items such as formed tube ends or wires and associated insulation and seals.
For purposes of inspecting formed ends on tubes, two conventional techniques have been used. The characteristics and quality of the formed end of the tube are important so that appropriate connections are made in the application of such tubes, for example. Conventional inspection techniques include mechanical gauges or camera-based systems. Tooling marks, lighting conditions and space requirements have rendered camera-based inspection systems difficult to apply. The typical environment within which such systems are proposed to be used are relatively harsh for such camera systems, which increases the maintenance and support required to operate such systems. Camera-based systems have proven generally too expensive and not practical.
Mechanical gauges for inspecting tube ends are limited in several ways. The mechanical nature of such devices render them prone to wear, degradation and mechanical failure over time. Further, such gauges are configured for specific mechanical part dimensions, which does not allow them to be used for a variety of products.
A further drawback associated with mechanical gauges and camera-based systems is that they require the part to be stationary during the inspection process, which increases overall production time and decreases overall production efficiencies.
Another application for inspection technology is for inspecting wire strips that are used in automotive applications, for example.
Wire strip inspection devices are well known and used in the industry in processing machines to monitor the quality of wires used in making electrical connections. The typical concern is to verify that the insulation of the wire has been properly removed. Conventional wire strip inspection devices include contact sensors where the exposed, conductive portion of the wire makes contact with two mechanical plates to form a connection that confirms that the insulation has been removed.
Other types of sensors have been utilized that do not require contact with the conductive portion of the wire. In conventional non-contact sensors, the wire is moved through a sensing window. The sensor head is mechanically positioned or aligned in the path of the insulation shoulder so that the insulation shoulder passes through the sensing window. Two sensing beams are typically utilized and positioned so that the insulation interrupts the first beam while the exposed conductive portion interrupts the second beam. A determination is made based upon a relative percentage between pulse width signals generated when the wire passes through the beams.
Previously used sensing devices, however, are not without shortcomings and drawbacks. For example, mechanical setup is required to specifically accommodate any change in the expected strip length of the wire. Moreover, an operator typically is required to utilize trial and error to mechanically adjust the sensor over the travel position of the wire so that the individual beams are incident on the expected portion of the wire. Additionally, the wire-processing machine must be precisely calibrated to move each wire sample through the sensor at the exact same position or erroneous results are achieved.
Existing sensor arrangements do not provide sufficiently economical operation because of the large amount of operator input and sophistication that is required. Moreover, the large amount of precise and tedious adjustment required to accommodate different wire sizes, tolerances and seal applications introduces additional down time of a machine and the associated costs in loss of production time.
Additionally, previous devices are not capable of detecting all of the characteristics of a wire that ideally are monitored as part of the inspection process. For example, previously used sensors may be capable of detecting the presence of a seal on a wire but cannot determine the seal's orientation or condition.
Accordingly, there is a need for an improved inspection device that has greater capabilities, is more effective and does not require a large amount of operator input or adjustment. This invention provides such a system and avoids the shortcomings and drawbacks of the prior art discussed above.